"I can't go any farther," she faltered; "there's a wall in front."
The poor girls were almost in despair. They had been so confident that the passage would surely be taking them to the outer world; to find themselves once more at a full stop was a terrible blow.
"Must we go all that dreadful long way back?" wailed Cicely.
"I expect there is some door that we've passed without knowing it," replied Lindsay, rather chokily.
"Then we can never find it in the dark. It's no use. We shall both starve to death here, and they'll discover our skeletons a hundred years afterwards."
Cicely had utterly broken down, and was sobbing bitterly.
"We won't give up too soon," said Lindsay, whose sturdy courage stood her in good stead on this occasion.
She had been feeling about here and there on the blank wall that faced them, and her fingers at last encountered something that seemed like a sliding bolt. She pushed it back eagerly. A door opened outwards, letting in a blaze of light. To their utter amazement they were gazing down into the picture gallery!
It did not take them many seconds to spring to the floor and turn round to look through what aperture they had made their escape. It was the portrait of Monica Courtenay that formed the secret exit. It had swung out, frame and all, into the gallery, and appeared to be fitted with hinges so as to close and unclose quite easily.
"Now I see why the picture shook in its frame that day!" exclaimed Cicely. "I wonder we never thought of this before."